Exhibiting instrument



July 26, 1938. w. R. scHoFlELD, JR

EXHIBITING INSTRUMENT Fild July 24, 1935 2 sheets-sneer 1 MIN July 26, 1938- w. R. scHoFlELD, JR 2,124,832

EXHIBITING INSTRMENT Filed July 24, 1935 2 Sheets-Sheet 2 29 I i 5 MR g1' J l v 35 32;L 57 v 38 36 m TT I I FU 4.? l: l l I 3 l A 3 17g?? H ma ILQIZZGI;

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Patented July 26, 1.938

PATENT OFFICE A2,124,832 y EXHIBITING INSTRUMENT William R. Schofield, Jr., Philadelphia, Pa., assgnor to Leeds and Northrup Company, llhiladelphia, Pa., a corporation of Pennsylvania.

Application July 24, 1935, Serial No. 32,8-34

4 Claims.

My invention relates to apparatus for indicating, recording the magnitude or changes in magnitude of a condition, and more particularly to apparatus of the type having a sensitive ele- 5 ment responsive to changes in magnitude of a condition, and a self-balancing system controlled thereby to effect movement of indicating and/or recording structure.

In accordance with one aspect of my invention, a rotatable indicator, a rotatable chart and a marker for the chart are carried by a movable frame to form a unit which, when in operating position, provides for driving of the chart by a suitable motor and for operative association of the indicator and marker with the relay of the instrument.

, My invention further resides in the features of construction, combination and arrangement hereinafter described and claimed.

, For an understanding of my invention reference is to be had to the accompanying drawings, in which: 1

Figure 1 is a front elevational view, with parts broken away, of an indicating-recording instrument;

Fig. 2 is a plan View, in section, of recording and indicating elements appearing in Fig. l;

Fig. '2a is a detail view, on enlarged scale, of parts appearing in Fig. 2';

Fig. 3 is a plan view of the operating mechanismrfor the indicating-recording mechanism;

Fig. 4 is a rear elevational view of the indicating-recording unit shown in Fig. 2;

Fig. 5 is a detail view'of parts appearing in Figs. l, 2 and 4;

Figs. G and 7 are, respectively, rear and side elevational views of the operating mechanism shown in Fig. 3.

Referring to Figs. l and 2, the casing I is provided at the right-hand side with lugs 2 for receiving the hinge pinsfor the pivoted frame 4. As more clearly appears in Figs. 2 and 4the central portion of the frame .member 4 provides a bearing for the hollow shaft 5, to one end of which is secured the gear 6 and the other end of which is secured to or integral with the driving plate 'I for a recorder chart C which is held against plate 'I by the clamping nut 9. The-gear 6 is in mesh with gear I0 driven by worm II on 50 one end'of shaft I2 to which is attached the gear I3 which engages the worm, I4 on `shaft I5 which extends through the upper lug I6 of the frame 4 and upper hinge lug 2 of the casing I. Gears 6, I0, II, I3 and shaft I2 are carried by the frame member 4 and form a unit which, when positioned in the casing, effects a driving connection between the chart C and the shaft I5. The member I'I (Figs. l, 2, 4 and 5) is supported bythe frame member 4 for pivotal movement about the pins I8, I8. Member I'I, as shown in Figs. 1 and 2, extends in front of the chart C and provides a bearing for the rotatable member I9 which, when the unit 4 is in position, and the member II swung to the position shown in Fig. 2, is coaxial with the shaft 20 which, as hereinafter appears, is rotated in accordance with the changes in magnitude of a condition, as temperature, pressure, ow, etc. To the rotatable member I9 is suitably secured the pointer P adapted to 'cooperate with the scale S which may, as shown in Fig. 2, be secured to the cover 2I of the instrument which, as appears in Fig. l,v is hinged at 8, 8 to the left-hand side of the casing I. 'I'he rotatable member I 9 is disengageably connected v to the rotatable shaft 20 as by the bolt 22, so that when the parts are in the normal operating position shown in Fig. 2, the pointer P will follow the changes in magnitude of the condition under measurement and indicate its instantaneous values.

The rotation of the shaft 20 is communicated to the marker M for chart C by the' cord 23 which, as'most clearly shown in Fig. 5, passes over the idler'pulley 24 whose shaft is carried by the member I'I' near the pivoted end thereof, over pulley 25 secured to or integral with the rotatable -member I9, and the idler pulley 26. Preferably, the 'carriage for the marker or pen is guided by the rod 28 spaced from and carried by 'the member I'I which is disposed so that the tip of the marker moves radiallyof the c hart C.

The frame 4 and the elements described vabove as being carried byit, constitute an indicatingrecording unit RI using a rotatable indicator and circular chart which may be used interchangeably with the strip-chart, llinear indicating unit disclosed. in 'Ross et al. application Serial No. 714,546, filed March'8, 1934 now U. S. Patent No. 2,074,118, dated March 16, 1937. The present unit is preferred when visibility of the indicator A is of primary importance and high accuracy or readibility of the record is of secondary importance. A

The basic unit BU of the instrument, which includes the mechanism for operating shaft 20 in accordance with the changes in magnitude of a condition, may be of the, step-by-step type .such as shown in Squibb Patent No. 1,935,732, or of the continuous adjustment type such as disclosed in Williams. application Serial No. .634,425

led September 22, 1932, or Williams et al. application Serial No. 602,424, filed April 1, 1932, and is preferably also pivotally mounted within the casing I and for movement about the same axis as the indicating-recording unit RI. The lugs 3, 3 of the frame 42 of the unit BU (Figs. 6 and 7) rest upon the lugs 2, 2 of the casing (Fig. 1).

As shown, the mechanical relay mechanism MR, Figs. 3 and 6, is of the type fully disclosed in the aforesaid Squibb Patent 1,935,732 and to which reference is made for a detailed description thereof. Therefore, only selected representative parts of that mechanism have been shown and briefly described. Thus it will be seen the motor 34, through a worm gear and cooperating gear (not shown), drives shaft 33 (Fig. 3) and through worm gear 35 and gear 36 (Fig. '7) drives shaft 3l and gear 38; the latter, through gear 39 (Fig. 1), Worm gear I4 and gear I3 (Fig. 4), drives shaft I2, worm gear II, gears I and 6, hollow shaft 5 (Figs. 2 and 4) and the chart-driving member The shaft 20 is rotated by or under the control of the mechanical relay MR. Its detector 29, for example, shown as a galvanometer responsive to unbalance of an electrical system or network, has a deiiecting member 30 whose deviation from a neutral position in response to change in magnitude of a condition causes corresponding rotation of the shaft 20. By turning knob 29a the deilecting member 30 may be adjusted to its zero position. Upon the disc 46 secured to shaft 29 is a slide-wire or resistance W engaged by a fixed contact, not shown, and included in balanceable network,

.such as a potentiometer or a Wheatstone bridge,

which also includes galvanometer 29 and a suitable condition-respcnsive device, as a thermocouple, a resistance-thermometer coil, or an ionconcentration cell, etc. for producing an electrical eect which is a function of the magnitude or change in magnitude of the condition under measurement. The'defiection of member 39 from neutral position, as more fully explained in the aforesaid Squibb Patent No. 1,935,732, causes the driving clutch member 3|, while out of engagement with the driven clutch member 39a, to be swung about the pivot 32a in one direction or the other depending upon the sense of deflection of member 30 and to an extent depending upon the angle of deection. Thereafter, and while the clutch members 30a, 3| are in engagement. one or the other of the cams 32 on shaft 33 driven by motor 34 engages the member 3| and restores it to its neutral position shown in Fig. 6. 4Since the clutch members 30a, 3| are in engagement during this movement, the shaft20, to one end of which the clutch disc' 30a is secured, is rotated in a sense and to an extent determined by the sense and extent of deflection of the member` 30. Upon a change in magnitude of the condition under measurement, the galvanometer 29 responds to .effect a rebalancing adjustment of slidewire W by causing operation of shaft 20 as above described.

T0 shaft 33, driven by motor 34, is attached the`worm gear 35 which meshes with gear 36 on shaft 31- near the rear of the unit BU and on which, adjacent the common pivotal axis of the units RI and BU, is secured the gear 3B in mesh with the gear 39 on the lower end of the shaft I which is coaxial with or may serve as the upper hinge pin for the two units, and to whose upper end, as previously described, is attached the worm I4 for driving the recorder chart C.

As shown in Fig. 3, the unit lBU may be maintained in proper position within the casing I by the screw 40 which passes through the extension V4| of the frame 42 of the unit BU and threadably engages the lug 43 extending from the interior of the casing I. When the instrument is to be of the round-chart rotatable-indicator type, the unit RI (Fig. 4) is added to the basic unit (Fig. 3). The mounting of the unit effects the driving connection between the motor 34 and the chart driving disk l by effecting engagement of gear I3 of unit RI with worm I4. When the unit RI is swung into position, it effects axial alignment of shaft 29 with the rotatable element I9 for the indicator and the marker. By turning the bolt A22, the indicator and marker are operatively connected to the shaft 20, and when the cover 2| is swung to position an annular scale S is brought into position coaxial with the pointer or indicator P. As appears from Fig. 1, the chart C is visible through the circular opening afforded by the scale S. The window 48 is held in the recess in the back of cover 2| by the scale S; preferably a gasket 49 of suitable resilient material is interposed between the margin of the window and the cover 2|.

Whenit is desired to replace the chart C, the cover 2| is swung open, the bolt 22 is loosened to permit the arm Il to be swung in clockwise direction about its pivot as viewed in Fig. 2, whereupon the nut 9 may be removed and a new chart mounted. By reversal of thiso sequence of operations, the marker and indicator are again coupled to shaft 20 and the scale S brought into proper relation with respect to the indicator P. Proper position of the indicator P with respect to shaft 2li is ensured as by an interlocking conextends into recess |9a of the member I9, Fig. 2a. Further, since the basic unit BU and the recording-indicating unit RI have a common pivotal axis, they may both be swung as a unitwith respect to the casing without disturbance of the operative conditions between them to afford access to and inspection of all parts of the mechanism while in operation or operative relation. The two units may be held in proper relative position as a. unit by a bolt or other suitable clamping means which passes through the lug 44, Fig.

4, of the recording-indicating unit, and lug 45, Fig. 3, of the basic unit.

While I have illustrated and described a preferred arrangement, it is to be understood my invention is not limited but is coextensive in scope with the appended claims.

What I claim is: i1. An instrument of the character described comprising .a rotatable shaft, means for actuating said shaft responsive to the changes in magnitude of a condition, a frame pivoted to swing about an axis substantially at right angles to said shaft,y a scale'carried by said frame, a member pivotaily mounted on said frame and extending in front of said scale, a rotatable element carried by said member and in axial alignment with said shaft when said frame and said member are in predetermined positions, means for disengageably connecting said rotatable shaft to said rotatable element,.and means connected to said rotatable element for movement in cooperative relation with said scale.

2. An instrument of the characterdescribed comprising a. rotatable shaft, means for actuating said shaft responsive to the changes in magnitude of a condition, a frame pivoted to "nection comprising lug 29a of shaft 29 which swing about an axis substantially at right angles to said shaft, a rotatable chart detachably carried by said frame and rotating coaxially with said shaft when said frame is swung to normal position, a member pivotally mounted on said frame and normally extending in frontof said chart, a rotatable element carried by said member and in axial augment with said shaft when said frame and said member are in normal positions, means for disengageably interlocking said rotatable shaft. and said rotatable element to form a driving connection therebetween, and a marker forsaid chart driven by said rotatable element.

3. An instrument of the character described comprising a rotatable shaft, means for actuating said shaft responsive to the changes in magnitude of a condition, a chart disposed in a plane normal to the axis of said shaft, a frame pivoted to swing about an axis substantially at right angles to said shaft, a member pivotally mounted on said frame, a rotatable element carried by said lmember centrally of said chart when said frame and said member are in normal positions, a marker operg5 atively connected to said element for cooperation with said chart when said frame and said member are in normal positions, and means forming a disengageable driving connection between said rotatable shaft and said rotatable element.

4. An instrument of the character described comprising a casing, a motor within said casing, means within said casing and including a shaft rotatable in accordance with changes in magnitude of a condition, a unit, pivoted with respect to said housing and said shaft, comprising a rotatable chart whose axis is parallel to that of said shaft when said unit is swung to normal position, a supporting member pivoted to said unit and extending in front of said chart, a marker slidably mounted on said supporting member, a driven member therefor coaxial with said chart when said unit and said supporting member are swung to their respective normal positions, and releasable means engaging said shaft and said driven member to form a 'driving connection therebetween, said member upon release of said driving connection being pivotally movable away from and into cooperative relation with said shaft.

WILLIAM R. SCHOFIELD, Jl.

unit and said supporting 

